1 /* Establishing and handling network connections.
2 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software
6 This file is part of GNU Wget.
8 GNU Wget is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 GNU Wget is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with Wget. If not, see <http://www.gnu.org/licenses/>.
21 Additional permission under GNU GPL version 3 section 7
23 If you modify this program, or any covered work, by linking or
24 combining it with the OpenSSL project's OpenSSL library (or a
25 modified version of that library), containing parts covered by the
26 terms of the OpenSSL or SSLeay licenses, the Free Software Foundation
27 grants you additional permission to convey the resulting work.
28 Corresponding Source for a non-source form of such a combination
29 shall include the source code for the parts of OpenSSL used as well
30 as that of the covered work. */
39 #include <sys/socket.h>
40 #include <sys/select.h>
45 # else /* def __VMS */
47 # endif /* def __VMS [else] */
48 # include <netinet/in.h>
50 # include <arpa/inet.h>
52 #endif /* not WINDOWS */
62 /* Apparently needed for Interix: */
67 /* Define sockaddr_storage where unavailable (presumably on IPv4-only
71 # ifndef HAVE_STRUCT_SOCKADDR_STORAGE
72 # define sockaddr_storage sockaddr_in
74 #endif /* ENABLE_IPV6 */
76 /* Fill SA as per the data in IP and PORT. SA shoult point to struct
77 sockaddr_storage if ENABLE_IPV6 is defined, to struct sockaddr_in
81 sockaddr_set_data (struct sockaddr *sa, const ip_address *ip, int port)
87 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
89 sin->sin_family = AF_INET;
90 sin->sin_port = htons (port);
91 sin->sin_addr = ip->data.d4;
97 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
99 sin6->sin6_family = AF_INET6;
100 sin6->sin6_port = htons (port);
101 sin6->sin6_addr = ip->data.d6;
102 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
103 sin6->sin6_scope_id = ip->ipv6_scope;
107 #endif /* ENABLE_IPV6 */
113 /* Get the data of SA, specifically the IP address and the port. If
114 you're not interested in one or the other information, pass NULL as
118 sockaddr_get_data (const struct sockaddr *sa, ip_address *ip, int *port)
120 switch (sa->sa_family)
124 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
127 ip->family = AF_INET;
128 ip->data.d4 = sin->sin_addr;
131 *port = ntohs (sin->sin_port);
137 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
140 ip->family = AF_INET6;
141 ip->data.d6 = sin6->sin6_addr;
142 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
143 ip->ipv6_scope = sin6->sin6_scope_id;
147 *port = ntohs (sin6->sin6_port);
156 /* Return the size of the sockaddr structure depending on its
160 sockaddr_size (const struct sockaddr *sa)
162 switch (sa->sa_family)
165 return sizeof (struct sockaddr_in);
168 return sizeof (struct sockaddr_in6);
175 /* Resolve the bind address specified via --bind-address and store it
176 to SA. The resolved value is stored in a static variable and
177 reused after the first invocation of this function.
179 Returns true on success, false on failure. */
182 resolve_bind_address (struct sockaddr *sa)
184 struct address_list *al;
186 /* Make sure this is called only once. opt.bind_address doesn't
187 change during a Wget run. */
188 static bool called, should_bind;
189 static ip_address ip;
193 sockaddr_set_data (sa, &ip, 0);
198 al = lookup_host (opt.bind_address, LH_BIND | LH_SILENT);
201 /* #### We should be able to print the error message here. */
202 logprintf (LOG_NOTQUIET,
203 _("%s: unable to resolve bind address %s; disabling bind.\n"),
204 exec_name, quote (opt.bind_address));
209 /* Pick the first address in the list and use it as bind address.
210 Perhaps we should try multiple addresses in succession, but I
211 don't think that's necessary in practice. */
212 ip = *address_list_address_at (al, 0);
213 address_list_release (al);
215 sockaddr_set_data (sa, &ip, 0);
222 const struct sockaddr *addr;
228 connect_with_timeout_callback (void *arg)
230 struct cwt_context *ctx = (struct cwt_context *)arg;
231 ctx->result = connect (ctx->fd, ctx->addr, ctx->addrlen);
234 /* Like connect, but specifies a timeout. If connecting takes longer
235 than TIMEOUT seconds, -1 is returned and errno is set to
239 connect_with_timeout (int fd, const struct sockaddr *addr, socklen_t addrlen,
242 struct cwt_context ctx;
245 ctx.addrlen = addrlen;
247 if (run_with_timeout (timeout, connect_with_timeout_callback, &ctx))
252 if (ctx.result == -1 && errno == EINTR)
257 /* Connect via TCP to the specified address and port.
259 If PRINT is non-NULL, it is the host name to print that we're
263 connect_to_ip (const ip_address *ip, int port, const char *print)
265 struct sockaddr_storage ss;
266 struct sockaddr *sa = (struct sockaddr *)&ss;
269 /* If PRINT is non-NULL, print the "Connecting to..." line, with
270 PRINT being the host name we're connecting to. */
273 const char *txt_addr = print_address (ip);
274 if (0 != strcmp (print, txt_addr))
276 char *str = NULL, *name;
278 if (opt.enable_iri && (name = idn_decode ((char *) print)) != NULL)
280 int len = strlen (print) + strlen (name) + 4;
282 snprintf (str, len, "%s (%s)", name, print);
287 logprintf (LOG_VERBOSE, _("Connecting to %s|%s|:%d... "),
288 str ? str : escnonprint_uri (print), txt_addr, port);
295 if (ip->family == AF_INET)
296 logprintf (LOG_VERBOSE, _("Connecting to %s:%d... "), txt_addr, port);
298 else if (ip->family == AF_INET6)
299 logprintf (LOG_VERBOSE, _("Connecting to [%s]:%d... "), txt_addr, port);
304 /* Store the sockaddr info to SA. */
305 sockaddr_set_data (sa, ip, port);
307 /* Create the socket of the family appropriate for the address. */
308 sock = socket (sa->sa_family, SOCK_STREAM, 0);
312 #if defined(ENABLE_IPV6) && defined(IPV6_V6ONLY)
315 /* In case of error, we will go on anyway... */
316 int err = setsockopt (sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof (on));
319 DEBUGP (("Failed setting IPV6_V6ONLY: %s", strerror (errno)));
323 /* For very small rate limits, set the buffer size (and hence,
324 hopefully, the kernel's TCP window size) to the per-second limit.
325 That way we should never have to sleep for more than 1s between
327 if (opt.limit_rate && opt.limit_rate < 8192)
329 int bufsize = opt.limit_rate;
331 bufsize = 512; /* avoid pathologically small values */
333 setsockopt (sock, SOL_SOCKET, SO_RCVBUF,
334 (void *)&bufsize, (socklen_t)sizeof (bufsize));
336 /* When we add limit_rate support for writing, which is useful
337 for POST, we should also set SO_SNDBUF here. */
340 if (opt.bind_address)
342 /* Bind the client side of the socket to the requested
344 struct sockaddr_storage bind_ss;
345 struct sockaddr *bind_sa = (struct sockaddr *)&bind_ss;
346 if (resolve_bind_address (bind_sa))
348 if (bind (sock, bind_sa, sockaddr_size (bind_sa)) < 0)
353 /* Connect the socket to the remote endpoint. */
354 if (connect_with_timeout (sock, sa, sockaddr_size (sa),
355 opt.connect_timeout) < 0)
361 logprintf (LOG_VERBOSE, _("connected.\n"));
362 DEBUGP (("Created socket %d.\n", sock));
367 /* Protect errno from possible modifications by close and
369 int save_errno = errno;
373 logprintf (LOG_VERBOSE, _("failed: %s.\n"), strerror (errno));
379 /* Connect via TCP to a remote host on the specified port.
381 HOST is resolved as an Internet host name. If HOST resolves to
382 more than one IP address, they are tried in the order returned by
383 DNS until connecting to one of them succeeds. */
386 connect_to_host (const char *host, int port)
391 struct address_list *al = lookup_host (host, 0);
396 logprintf (LOG_NOTQUIET,
397 _("%s: unable to resolve host address %s\n"),
398 exec_name, quote (host));
402 address_list_get_bounds (al, &start, &end);
403 for (i = start; i < end; i++)
405 const ip_address *ip = address_list_address_at (al, i);
406 sock = connect_to_ip (ip, port, host);
410 address_list_set_connected (al);
411 address_list_release (al);
415 /* The attempt to connect has failed. Continue with the loop
416 and try next address. */
418 address_list_set_faulty (al, i);
421 /* Failed to connect to any of the addresses in AL. */
423 if (address_list_connected_p (al))
425 /* We connected to AL before, but cannot do so now. That might
426 indicate that our DNS cache entry for HOST has expired. */
427 address_list_release (al);
428 al = lookup_host (host, LH_REFRESH);
431 address_list_release (al);
436 /* Create a socket, bind it to local interface BIND_ADDRESS on port
437 *PORT, set up a listen backlog, and return the resulting socket, or
440 BIND_ADDRESS is the address of the interface to bind to. If it is
441 NULL, the socket is bound to the default address. PORT should
442 point to the port number that will be used for the binding. If
443 that number is 0, the system will choose a suitable port, and the
444 chosen value will be written to *PORT.
446 Calling accept() on such a socket waits for and accepts incoming
450 bind_local (const ip_address *bind_address, int *port)
453 struct sockaddr_storage ss;
454 struct sockaddr *sa = (struct sockaddr *)&ss;
456 /* For setting options with setsockopt. */
458 void *setopt_ptr = (void *)&setopt_val;
459 socklen_t setopt_size = sizeof (setopt_val);
461 sock = socket (bind_address->family, SOCK_STREAM, 0);
466 setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, setopt_ptr, setopt_size);
470 sockaddr_set_data (sa, bind_address, *port);
471 if (bind (sock, sa, sockaddr_size (sa)) < 0)
476 DEBUGP (("Local socket fd %d bound.\n", sock));
478 /* If *PORT is 0, find out which port we've bound to. */
481 socklen_t addrlen = sockaddr_size (sa);
482 if (getsockname (sock, sa, &addrlen) < 0)
484 /* If we can't find out the socket's local address ("name"),
485 something is seriously wrong with the socket, and it's
486 unusable for us anyway because we must know the chosen
491 sockaddr_get_data (sa, NULL, port);
492 DEBUGP (("binding to address %s using port %i.\n",
493 print_address (bind_address), *port));
495 if (listen (sock, 1) < 0)
503 /* Like a call to accept(), but with the added check for timeout.
505 In other words, accept a client connection on LOCAL_SOCK, and
506 return the new socket used for communication with the client.
507 LOCAL_SOCK should have been bound, e.g. using bind_local().
509 The caller is blocked until a connection is established. If no
510 connection is established for opt.connect_timeout seconds, the
511 function exits with an error status. */
514 accept_connection (int local_sock)
518 /* We don't need the values provided by accept, but accept
519 apparently requires them to be present. */
520 struct sockaddr_storage ss;
521 struct sockaddr *sa = (struct sockaddr *)&ss;
522 socklen_t addrlen = sizeof (ss);
524 if (opt.connect_timeout)
526 int test = select_fd (local_sock, opt.connect_timeout, WAIT_FOR_READ);
532 sock = accept (local_sock, sa, &addrlen);
533 DEBUGP (("Accepted client at socket %d.\n", sock));
537 /* Get the IP address associated with the connection on FD and store
538 it to IP. Return true on success, false otherwise.
540 If ENDPOINT is ENDPOINT_LOCAL, it returns the address of the local
541 (client) side of the socket. Else if ENDPOINT is ENDPOINT_PEER, it
542 returns the address of the remote (peer's) side of the socket. */
545 socket_ip_address (int sock, ip_address *ip, int endpoint)
547 struct sockaddr_storage storage;
548 struct sockaddr *sockaddr = (struct sockaddr *) &storage;
549 socklen_t addrlen = sizeof (storage);
552 memset (sockaddr, 0, addrlen);
553 if (endpoint == ENDPOINT_LOCAL)
554 ret = getsockname (sock, sockaddr, &addrlen);
555 else if (endpoint == ENDPOINT_PEER)
556 ret = getpeername (sock, sockaddr, &addrlen);
562 ip->family = sockaddr->sa_family;
563 switch (sockaddr->sa_family)
568 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)&storage;
569 ip->data.d6 = sa6->sin6_addr;
570 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
571 ip->ipv6_scope = sa6->sin6_scope_id;
573 DEBUGP (("conaddr is: %s\n", print_address (ip)));
579 struct sockaddr_in *sa = (struct sockaddr_in *)&storage;
580 ip->data.d4 = sa->sin_addr;
581 DEBUGP (("conaddr is: %s\n", print_address (ip)));
589 /* Get the socket family of connection on FD and store
590 Return family type on success, -1 otherwise.
592 If ENDPOINT is ENDPOINT_LOCAL, it returns the sock family of the local
593 (client) side of the socket. Else if ENDPOINT is ENDPOINT_PEER, it
594 returns the sock family of the remote (peer's) side of the socket. */
597 socket_family (int sock, int endpoint)
599 struct sockaddr_storage storage;
600 struct sockaddr *sockaddr = (struct sockaddr *) &storage;
601 socklen_t addrlen = sizeof (storage);
604 memset (sockaddr, 0, addrlen);
606 if (endpoint == ENDPOINT_LOCAL)
607 ret = getsockname (sock, sockaddr, &addrlen);
608 else if (endpoint == ENDPOINT_PEER)
609 ret = getpeername (sock, sockaddr, &addrlen);
616 return sockaddr->sa_family;
619 /* Return true if the error from the connect code can be considered
620 retryable. Wget normally retries after errors, but the exception
621 are the "unsupported protocol" type errors (possible on IPv4/IPv6
622 dual family systems) and "connection refused". */
625 retryable_socket_connect_error (int err)
627 /* Have to guard against some of these values not being defined.
628 Cannot use a switch statement because some of the values might be
632 || err == EAFNOSUPPORT
635 || err == EPFNOSUPPORT
637 #ifdef ESOCKTNOSUPPORT /* no, "sockt" is not a typo! */
638 || err == ESOCKTNOSUPPORT
640 #ifdef EPROTONOSUPPORT
641 || err == EPROTONOSUPPORT
644 || err == ENOPROTOOPT
646 /* Apparently, older versions of Linux and BSD used EINVAL
647 instead of EAFNOSUPPORT and such. */
652 if (!opt.retry_connrefused)
653 if (err == ECONNREFUSED
655 || err == ENETUNREACH /* network is unreachable */
658 || err == EHOSTUNREACH /* host is unreachable */
666 /* Wait for a single descriptor to become available, timing out after
667 MAXTIME seconds. Returns 1 if FD is available, 0 for timeout and
668 -1 for error. The argument WAIT_FOR can be a combination of
669 WAIT_FOR_READ and WAIT_FOR_WRITE.
671 This is a mere convenience wrapper around the select call, and
672 should be taken as such (for example, it doesn't implement Wget's
673 0-timeout-means-no-timeout semantics.) */
676 select_fd (int fd, double maxtime, int wait_for)
679 fd_set *rd = NULL, *wr = NULL;
680 struct timeval tmout;
685 if (wait_for & WAIT_FOR_READ)
687 if (wait_for & WAIT_FOR_WRITE)
690 tmout.tv_sec = (long) maxtime;
691 tmout.tv_usec = 1000000 * (maxtime - (long) maxtime);
695 result = select (fd + 1, rd, wr, NULL, &tmout);
697 /* gnulib select() converts blocking sockets to nonblocking in windows.
698 wget uses blocking sockets so we must convert them back to blocking. */
699 set_windows_fd_as_blocking_socket (fd);
702 while (result < 0 && errno == EINTR);
707 /* Return true iff the connection to the remote site established
708 through SOCK is still open.
710 Specifically, this function returns true if SOCK is not ready for
711 reading. This is because, when the connection closes, the socket
712 is ready for reading because EOF is about to be delivered. A side
713 effect of this method is that sockets that have pending data are
714 considered non-open. This is actually a good thing for callers of
715 this function, where such pending data can only be unwanted
716 leftover from a previous request. */
719 test_socket_open (int sock)
725 /* Check if we still have a valid (non-EOF) connection. From Andrew
726 * Maholski's code in the Unix Socket FAQ. */
728 FD_ZERO (&check_set);
729 FD_SET (sock, &check_set);
731 /* Wait one microsecond */
735 ret = select (sock + 1, &check_set, NULL, NULL, &to);
737 /* gnulib select() converts blocking sockets to nonblocking in windows.
738 wget uses blocking sockets so we must convert them back to blocking
740 set_windows_fd_as_blocking_socket ( sock );
744 /* We got a timeout, it means we're still connected. */
747 /* Read now would not wait, it means we have either pending data
752 /* Basic socket operations, mostly EINTR wrappers. */
755 sock_read (int fd, char *buf, int bufsize)
759 res = read (fd, buf, bufsize);
760 while (res == -1 && errno == EINTR);
765 sock_write (int fd, char *buf, int bufsize)
769 res = write (fd, buf, bufsize);
770 while (res == -1 && errno == EINTR);
775 sock_poll (int fd, double timeout, int wait_for)
777 return select_fd (fd, timeout, wait_for);
781 sock_peek (int fd, char *buf, int bufsize)
785 res = recv (fd, buf, bufsize, MSG_PEEK);
786 while (res == -1 && errno == EINTR);
794 DEBUGP (("Closed fd %d\n", fd));
800 /* Reading and writing from the network. We build around the socket
801 (file descriptor) API, but support "extended" operations for things
802 that are not mere file descriptors under the hood, such as SSL
805 That way the user code can call fd_read(fd, ...) and we'll run read
806 or SSL_read or whatever is necessary. */
808 static struct hash_table *transport_map;
809 static unsigned int transport_map_modified_tick;
811 struct transport_info {
812 struct transport_implementation *imp;
816 /* Register the transport layer operations that will be used when
817 reading, writing, and polling FD.
819 This should be used for transport layers like SSL that piggyback on
820 sockets. FD should otherwise be a real socket, on which you can
821 call getpeername, etc. */
824 fd_register_transport (int fd, struct transport_implementation *imp, void *ctx)
826 struct transport_info *info;
828 /* The file descriptor must be non-negative to be registered.
829 Negative values are ignored by fd_close(), and -1 cannot be used as
833 info = xnew (struct transport_info);
837 transport_map = hash_table_new (0, NULL, NULL);
838 hash_table_put (transport_map, (void *)(intptr_t) fd, info);
839 ++transport_map_modified_tick;
842 /* Return context of the transport registered with
843 fd_register_transport. This assumes fd_register_transport was
844 previously called on FD. */
847 fd_transport_context (int fd)
849 struct transport_info *info = hash_table_get (transport_map, (void *)(intptr_t) fd);
853 /* When fd_read/fd_write are called multiple times in a loop, they should
854 remember the INFO pointer instead of fetching it every time. It is
855 not enough to compare FD to LAST_FD because FD might have been
856 closed and reopened. modified_tick ensures that changes to
857 transport_map will not be unnoticed.
859 This is a macro because we want the static storage variables to be
862 #define LAZY_RETRIEVE_INFO(info) do { \
863 static struct transport_info *last_info; \
864 static int last_fd = -1; \
865 static unsigned int last_tick; \
866 if (!transport_map) \
868 else if (last_fd == fd && last_tick == transport_map_modified_tick) \
872 info = hash_table_get (transport_map, (void *)(intptr_t) fd); \
875 last_tick = transport_map_modified_tick; \
880 poll_internal (int fd, struct transport_info *info, int wf, double timeout)
883 timeout = opt.read_timeout;
887 if (info && info->imp->poller)
888 test = info->imp->poller (fd, timeout, wf, info->ctx);
890 test = sock_poll (fd, timeout, wf);
899 /* Read no more than BUFSIZE bytes of data from FD, storing them to
900 BUF. If TIMEOUT is non-zero, the operation aborts if no data is
901 received after that many seconds. If TIMEOUT is -1, the value of
902 opt.timeout is used for TIMEOUT. */
905 fd_read (int fd, char *buf, int bufsize, double timeout)
907 struct transport_info *info;
908 LAZY_RETRIEVE_INFO (info);
909 if (!poll_internal (fd, info, WAIT_FOR_READ, timeout))
911 if (info && info->imp->reader)
912 return info->imp->reader (fd, buf, bufsize, info->ctx);
914 return sock_read (fd, buf, bufsize);
917 /* Like fd_read, except it provides a "preview" of the data that will
918 be read by subsequent calls to fd_read. Specifically, it copies no
919 more than BUFSIZE bytes of the currently available data to BUF and
920 returns the number of bytes copied. Return values and timeout
921 semantics are the same as those of fd_read.
923 CAVEAT: Do not assume that the first subsequent call to fd_read
924 will retrieve the same amount of data. Reading can return more or
925 less data, depending on the TCP implementation and other
926 circumstances. However, barring an error, it can be expected that
927 all the peeked data will eventually be read by fd_read. */
930 fd_peek (int fd, char *buf, int bufsize, double timeout)
932 struct transport_info *info;
933 LAZY_RETRIEVE_INFO (info);
934 if (!poll_internal (fd, info, WAIT_FOR_READ, timeout))
936 if (info && info->imp->peeker)
937 return info->imp->peeker (fd, buf, bufsize, info->ctx);
939 return sock_peek (fd, buf, bufsize);
942 /* Write the entire contents of BUF to FD. If TIMEOUT is non-zero,
943 the operation aborts if no data is received after that many
944 seconds. If TIMEOUT is -1, the value of opt.timeout is used for
948 fd_write (int fd, char *buf, int bufsize, double timeout)
951 struct transport_info *info;
952 LAZY_RETRIEVE_INFO (info);
954 /* `write' may write less than LEN bytes, thus the loop keeps trying
955 it until all was written, or an error occurred. */
959 if (!poll_internal (fd, info, WAIT_FOR_WRITE, timeout))
961 if (info && info->imp->writer)
962 res = info->imp->writer (fd, buf, bufsize, info->ctx);
964 res = sock_write (fd, buf, bufsize);
973 /* Report the most recent error(s) on FD. This should only be called
974 after fd_* functions, such as fd_read and fd_write, and only if
975 they return a negative result. For errors coming from other calls
976 such as setsockopt or fopen, strerror should continue to be
979 If the transport doesn't support error messages or doesn't supply
980 one, strerror(errno) is returned. The returned error message
981 should not be used after fd_close has been called. */
986 /* Don't bother with LAZY_RETRIEVE_INFO, as this will only be called
987 in case of error, never in a tight loop. */
988 struct transport_info *info = NULL;
990 info = hash_table_get (transport_map, (void *)(intptr_t) fd);
992 if (info && info->imp->errstr)
994 const char *err = info->imp->errstr (fd, info->ctx);
997 /* else, fall through and print the system error. */
999 return strerror (errno);
1002 /* Close the file descriptor FD. */
1007 struct transport_info *info;
1011 /* Don't use LAZY_RETRIEVE_INFO because fd_close() is only called once
1012 per socket, so that particular optimization wouldn't work. */
1015 info = hash_table_get (transport_map, (void *)(intptr_t) fd);
1017 if (info && info->imp->closer)
1018 info->imp->closer (fd, info->ctx);
1024 hash_table_remove (transport_map, (void *)(intptr_t) fd);
1026 ++transport_map_modified_tick;